Plying



June 7, 1960 N. E. KLEIN 2,939,267

FLYING Filed Dec. 16, 1953 2 Sheets-Sheet 1 INVENTOR. NORMAN E. KLEIN BY Mi KM ATTORNEY June 7, 1960 N. E. KLEIN 2,939,267

FLYING Filed Dec. 16, 1953 2 Sheets Sheet 2 INVENTOR. NORMAN E.KLEIN BY 4M2 5m ATTORNEY of a rapidly rotating spindle.

United States Patent PLYING Norman E. Klein, Pendleton, S.C., assignor to Deering Milliken Research Corporation, Pendleton, S.C., a corporation of Delaware Filed Dec. 16, 1953, Ser. No. 398,569

18 Claims. (Cl. 57-583) This invention relates to improved mechanisms and methods for plying together a number of strands to form a plied strand and more particularly to mechanisms for plying together a number of strands without appreciably changing the twist of the individual strands.

The invention is applicable to readily flexible strands of substantially any composition or construction .and is particularly applicableto strands of cotton, rayon, nylon or other textile materials. All such strands are referred to in this specification and claims simply as yarns and it is intended that this term include all filaments or assemblages of filaments or fibers, either natural or manufactured.

In the preparation of yarns for use in the manufacture of automobile tires, industrial belts and in many other instances it is desirable to ply together two or more strands to form a heavier plied strand. This is presently accomplished, in most instances, by a multistep process wherein the individual strands are given a Z twist and then twisted together in S twist. Such a process has many well recognized disadvantages. For example, it requires several steps, it requires the rotation of large packages at high speeds, and it requires that the twisted strands be retained under tension for con- :siderable periods of time.

It has been previously suggested that these difiiculties could be overcome by plying together the strands of yarn by rotatinga balloon of one strand of yarn from a first :supply package about a second supply package to there- -by twist together the strands from said first supply package and said second supply package. The mechanisms :suggested by the prior art for accomplishing this result have, however, met with no considerable degree of commercial success because of, for one reason, the difiiculties encountered in obtaining a uniform plying together -of the strands.

According to this invention there is provided means, for instance a rotating spindle, for rotating at a substantially constant velocity a balloon of one strand of yarn from a first supply package about a second supply 'package to thereby twist together the strands from said first supply package and said second supply package at :the apex of the balloon, means for retainingthe tension in the balloon substantially constant, means for adjusting the tension in the strand of yarn from said second supply package to substantially equal the tension in said :strand of yarn in said balloon and means for withdrawing the plied strand under tension at a substantially constant linear rate. While the invention is particularly suitable for plying together two strands, it can be adapted to the plying of three or more strands.

Prior'art devices for twisting strands together by rotating a balloon of a strand from a first supply package about a second yarn supply package have resulted in the two strands being brought together in an axial passage It is a feature of this invention that the strands from the first and second 2,939,267 Patented June 7, 19 g supply packages are brought together for plying at substantially the apex of the balloon and it is this feature that makes possible the novel combination of tension control means to be more particularly described in subsequent paragraphs.

Heretofore the balloon of one strand of yarn has been employed only as a means of rotating a first strand of yarn about a second supply package of yarn to thereby twist the individual strands together and balloon tension has generally not been regulated. It is' a novel feature of this invention that means are provided to retain the tension in the strand of yarn in the balloon substantially constant and the constant balloon tension permits this I strand to be plied with others employing the balloon tension as a standard.

It is another feature of the invention that the balloon size is retained substantially constant by tension control in the strand in the balloon and the prior art problem of preventing the balloon from growing in size is thereby eliminated.

A further feature of the invention is that it does not require complex metering devices or complex tension equalizing devices.

A still further feature of the invention is that it pro vides for withdrawing the plied strand at a constant linear rate rather than at a constant tension. This makes possible greatly simplified apparatus and while some prior art devices have had this feature, others have required complex apparatus for withdrawing the plied strand a a variable rate under constant tension.

A feature of one embodiment of the invention isan improved tension equalizing device with no moving parts that does not require damping means and that can be rotated at high velocities without impairing its operating efiiciency. Prior art tension equalizing devices generally require moving parts and can therefore'not be readily rotated at high velocities without loss ofefiiciency due to the high frequency vibration and the practical impossibility of obtaining a perfect weight balance in all moving parts on each side of the axis of rotation.

Other features and advantages of the invention, as well as details of construction of several preferred embodiments, will become apparent from the following description when read in connection with the accompany ing drawings in which:

Figure 1 is a side elevation, with parts broken away and in section, of adevice suitable for plying together two strands of yarn.

Figure 2 is an enlarged elevational view, with par broken away and in section, of a selected portion of a device substantially identical in most respects to that iilustrated in Figure l but employing a modified arr-angement of yarn guides.

Figure 3 is also an enlarged elevational partial View, with parts broken away and in section, of a selected portion of a device substantially identical to that illustrated in Figure 1 but employing a revolving fiyer in place of a single pig-tail guide to bring the two strands together.

Figure 4 is a side elevational with parts broken away and in section of a modified form of the invention employing a novel yarn tension equalizing device adapted to equalize the tension of two strands of yarn being plied into one.

Figure 5 is an enlarged view in perspective of the new yarn tension equalizing device employed in the mechanism illustrated in Figure 4.-

With particular reference to Figure 1 of the drawings, the reference numeral 10 represents a stationary shaft mounted through a suitable orifice in a support member 11, the shaft 10 being retained in positionby a substantially in axial alignment with spindle 16.

bolster 12, lock-nuts 13 and 14, and spring 15. The spring :15 gives a certain degree of resiliency to the mounting. Atubular spindle 16 is journaled about the ,shaft 1 on antifrictionibearings such as the ball bearings port pin 23 adapted to hold a yarn supply package such as cylindrical bobbin 24' carrying'a supply of yarn 25.

The support platform 22 is prevented from rotating with v thespindle 16 by any suitable means such-as for instance mountingv the entire device at an angle to the vertical and placing a weight 26 eccentric'ally-on theplatform soithat the platform- -is{ prevented by gi avity from rotating. 7 a

type disclosed in my above-mentioned copending application Serial Number 13 2,226, now U.S. Patent No. 2,73 8,141.

So that the balloon 40 will not become ensnarled in the tension control device 47 or the other members supported by the support platform 22, there is provided a cover 53 mounted on the support platform 22 and having substantially the same shape asthe balloon 40. The cover 53 is preferably made of transparent plastic material so that the operation of the memberson the support platform 22 can 'be'observed. The lower peripheral rim of the cover 53 is adapted to sit in a groove 54 on the peripheral edge of the support platform 22 so that the cover may be lifted for access to the devices carried by the support platform. a The cover 53 is also provided with an orifice 55 at its apex through which strand 52, after 7 Mounted below the shaft to 011 s s'uita'ble support 'fne nber 2735 a pig-fail guide 28 having its eye z9 subs'tantially' in axial alignment with the shaft 10. a Mounted between the pigtail guide 28 and; the shaft subs'tantiall'y in axial' alignment' with the shaft 11% is an automatic tension control device indicated generally by the reference numeral '30. As; the precise construction of this automatic tension control does not constitute a part of the present invention it is illustrated only schematical- 1y as having a number offixed bars 31 and av number of movable bars 32 through which a strand of yarn 33 from a-yarn supply package '34 may be threaded. The

* tension controldevice 30 may be and preferably is the type disclosed in'my copending application Serial Number 132,226, filed December 1 0, 1949, now U.S. Patent No. 2,738,141, to which reference/may be had for details of construction.

' Rigidly mountedon spindle '16 immediately below the s'upport-platform 22 is'ayarn storage device 35 adapted to recei-ve' a strand of yarn passed through an axial- "passage 36 inshaft 10, an axial passage'37 in spindle 16 and through anorifice 38 in the wall of spindle 16. The yarn storage device 35 is preferably of an eccentric two- 's'tep design of the type disclosed and claimed in my cope'nding application Serial Number 244,812, filed September 1, 195.1, now U.S. Patent No. 2,8ll-,013, reference to which may be had for details of construction. The eccentric two-step type of yarn storage device is advantageous in that it may be more readily employed with a wide range of sizes and types of yarn, results in a more stable balloon, and is capable of holding up to one and oneehalf turnsof yarn. a

Mounted'on shaft 16. immediately above yarn storage device 35 and below support platform 22 is a flyer 39 preferably of the disk type, adapted to assist in shaping and controlling. a ballloon 40 of a strand of yarnextending from the yarn storage device 35 to the eye 41 o a p a l uide mount d on u t l po 43. The pig-tail guide 42' is provided with a pivot 44 so that it may be turned from operative position when the mechanism is not in operation.

Mounted. on the support platform 22, for example by pressed fit into an orifice in Weight 26, is a pig-tail guide 45 having an eye 46 positioned above the bobbin 24 and An adjustable automatic yarn tension control device 47 is positionedimmediatelyabove the eyer46 of the pig-tail vguide 45 andis secured in position by rod 48 press-fitted into a larger cylindrical member 49 which in turn is atas e o tanc wel in r qr u po pla .this'invention and it is indicated only schematically as having a number of fixed pins 50wand-movable pins 51 wrongs which a strand of yarn 52 from yarn supply package 25 is adapted to be passed. This automatic tens'ion control device may also be and preferably isof the passing through tension control device 47, may be passed. a I .7 I

e s ndi ted y metastases num al 5 a conventional traverse bar which; provides means for evenly winding the plied yarn 57' on bobbin 58. The bobbin 58, employed for the, purpose of collecting the plied yarn, is driven by contact of the yarn surface 59 onithe bobbin 58 with a drive roll 60 Whichis rotated at a constant velocity by any suitable means. As will be apparent to those skilled in; the art, this insures that the plied strand 57will be withdrawn at a constant linear rate.

To place the mechanism illustrated in Figure 1 in operation, a yarn end 33 from the yarn supply package 34 is twisted about one end of a semifiexible threading tube, commonly referred to asa snake. The strand of yarn 33; from the package 34' is then led through the eye 29 of the pig-tail guide 28 and then threaded through the 'mernbersof the automatic tension control device The snake is then passed into the lower end of the shaft 10 through the passage 36 and into the passage 37 in spindle 16. On striking the upper end of the passage 37 the snake is forced through the 'orifiee 38 and as the snake is pulled through, the strand is threaded into the proper flow path; The strand is then led to the outer peripheral'edgebfthe disc flyer 39 and'then through the eye .41 of the pig-tail guide 42. The strand is then passed over traverse bar 56 and wrapped a few turns around the spool 58. f

When placing the device in operation for the first time it will generally be advantageous at this point to make a rough adjustment of the automatic tension control device 30. This can be done by moving the spindle 16 into operative position against belt 19 so that the spindle is rotated at a high velocity. The spool 58 is then lowered against roll 60 and the tension control device 30 adjusted to give a balloon of approximately the desired size. The spool 58 is then removed from contact with roll 66 and rotationv of the spindle is stopped. If the mechanism has been in previous operation with strands of substantially the same type, the tension in the strand emerging from "the spindle '16- will generally be close enough to the correct value to make adjustment at this time unnecessary.

After the first strand 33 has been threadedthrough the mechanism and. an approximate adjustment, of tension has been made, the pig-tail guide 42 isturnedon pivot 44 so that the .cover 53 can be removed from operative position. A yarn end52 fromsupply package 25 is then threaded through the eye46of-pig-tail guide 45 and then through the automatictension control device 47. A rough adjustment should be made at this point so that the tension necessary to pull .the .strand from supply Package 25 through the eye 46 and the tension control meansi 47 is approximately the same as. that :required; to, pull the first strand 33 through its proper flow path. The yarn end from the supply package s2 s then threaded through orifice 55 in cover 53,and then through the eye- 41 of P guide 42. The cover the -:rep asssl n pig-tail guide 42 lowered into operative position. The yarn end from supply package is then led over the traverse bar 56 and given a few turns around spool 58 alongside the first strand. The device should then be placed in operation and automatic tension control adjusted to give a proper size balloon with the least amount of flutter.

If an evenly plied strand is desired, it is necessary that the tension in the strand 52 exactly equal the tension in the strand 33 since otherwise the strand with the lesser tension will be wrapped around the other with the strand having the greater tension forming a core. While it is a feature of this invention that the tension in strands 33 and 52 will remain equal once so adjusted, it isfirst necessary to equalize the tension in strands 33 and 52 as they enter the eye 41 and this is preferably accomplished primarily by trial and error adjustment of the tension control device 47. The reasons for this will be more fully explained in subsequent paragraphs.

The yarn storage device 35 when employed in the manner contemplated in this invention not only drives the balloon but also serves as a non-adjustable automatic tension control responsive to variations of tension in the strand 33 as it emerges from the orifice 38 and also responsive to variations in the size of the balloon 40 to thereby control the size of the balloon. As will be understood by those skilled in the art, if the size of the balloon is retained constant, the tension in the yarn comprising the balloon also remains constant. For example, if the input tension in strand 33 should decrease without being properly regulated by the automatic tension control 30 the balloon will tend to increase in size thereby causing more air drag and a resulting increase of wrap around on the yarn storage device. The increase in warp around is accompanied by a corresponding increase in tension, which tends to bring the balloon back to the original size. In view of this it will be apparent that the primary purpose of the automatic tension control means 30 is to retain the tension in the strand of yarn 33 as it emerges from the orifice 38 within the best limits capable of being handled by the yarn storage device 35 and that it is impossible to greatly change the tension in the yarn of the balloon 40 by adjustment of the tension control means 30 when the apparatus is operating properly. In other words, if one attempts to obtain an appreciably larger balloon by lessening the tension on strand 33 by adjustment of the tension control means 30, the yarn storage device 35 will substantially correct for the decreased tension by increased wrap around and retain the balloon size substantially constant.

In view of the above, it will be apparent that the primary method of equalizing the tension in strands 52 and 33 as they enter pig-tail guide 41 is by adjustment of the variable tension control means 47. This may be readily accomplished by trial and error since it is apparent from observation of the plied strand 57 whether or not the tensions in strands 52 and 33 are equal and if they are not, in which the tension is greater. If for example it is observed that the strand 52 is serving as a core in the plied strand 57 and that strand 33 is simply being wrapped around strand 52, it is apparent that the tension in strand 52 is too high and should be decreased. This is accomplished by removing the spindle 16 from contact with the belt 19 to stop its rotation, raising-the cover 53 and making the proper adjustments on automatic tension control device 47. The cover 53 is then lowered into operative position and operation of the device again initiated, making further adjustments if necessary. Once the tensions in the two strands are properly adjusted, they will remain so since, as previously explained, the tension in the balloon is retained at a constant value by the yarn storage device 35, and the tension control device 47 6 automatically retains a tension in strand 52 equal to the value to which it is originally adjusted.

Although tension equalization is primarily accomplished by adjusting the tension in strand 52, small adjustments can also be made in the tension in strand 33 by raising or lowering the pig-tail guide 42 to change balloon size and thereafter making a corresponding adjustment in tension control 30. In fact, small changes in the tension in strand 33 can be made simply by adjustment of the tension control 30 if an eccentric two-step yarn storage device is employed. This is possible because of the eccentric design of the yarn storage device which, while having many advantages, results in slight differences in' balloon size for very large differences in wrap around. However, adjustment of the tension control 30 to obtain tension equalization is generally not advantageous since, with a given size and type of yarn, there is an optimum range of wrap around for maximum balloon stability and tension control 30 is preferably employed only to insure that wrap around in the yarn storage device 35 is within the optimum range. As previously indicated, this is accomplished by adjusting tension control 30 to give a balloon with the smallest amount of flutter. Once the wrap around in the yarn storage device 35 is adjusted to be within the optimum range, the fluctuations in the tension in the yarn entering the yarn storage device are generally of such small magnitude that the device operates at near maximum efficiency at all times.

When the tensions in the individual strands 52 and 33 are equal, the strands are evenly displaced oneby the other resulting in the plied strand 57 consisting of two evenly interlayed helices of yarn having substantially the same twist in the individual strands as was originally present except for that imparted by removal of the strands-from the yarn supply packages. Further, since the balloon rotates at a substantially constant velocity, thereby resulting in a constant number of turns of the two strands 33 and 52 one about the other in a given period of time, and since the plied strand 57 is withdrawn under tension at a constant linear velocity as previously explained, it will be apparent to those skilled in the art that not only is the plied strand 57 uniform with respect to the displacement of one strand by the other but that in the plied yarn the two strands are twisted about each other a constant number of times per unit length. In other words this invention makes possible a plied yarn completely uniform in every respect.

In Figure 2 of the drawings there is partially illustrated a modified form of the invention wherein a strand of yarn 61 from a yarn supply source on a stationary platform, not illustrated, is passed through an automatic tension control device 62 and out a passageway at the apex of a cover 63 to be plied together with a second strand 64 being rotated in the form of a balloon. The device in Figure 2 differs from that in Figure l in that the simple orifice 55 and the pig-tail 42 in Figurel have been replaced respectively with a low friction trumpet generally indicated at 65 and a forming trumpet generally indicated at 66. The modification of Figure 2 is especially adapted for Winding highly plied yarns wherein the apex of the balloon may tend to ride down the plied strand 67 until it is bearing on the plastic cover. The advantages of the modification in Figure 2 in this regard will be made clear in the following discussion.

Referring to Figure 2 in greater detail, a tubular member 68 is rigidly afiixed in a suitable orifice in the upper extremity of the cover 63 which is mounted on a stationary support platform, not illustrated. Journaled in the member 68 is a yarn trumpet 69 which is freely rotatable by virtue of low friction bearings such as ball bearings illustrated at 70 and 71. The trumpet 69 has an axial passageway 72 adapted to receive the strand of yarn 61 and upper lip 73 designed to present a smooth surface for the strand 64 should it be forced down upon the trumpet opening. 'Matcliing grooves are in Fig tire 7 by th i fiwi inlhfi a eqstren 67 il 1 3 7% designed "so that the angle of strand-64 r$Pect to pl ed st d '67 lwilfs'omew at approi rimate. 'ngle of with respect to the plied yfardd? the tens ions therein are equal. With furthef rferencelto Figure 2, a movable. block 74 is resilie tly pressed against a i'lzieciblbck 75, by means orspriiagmnouhtea around a pin 77 ernia'nejhtly afiig'ied to the block74'f orfexaniple by pres f fit intofa'fsuitable hined in" blocks" 74 hen pressed-togeth there is formed a the plied trand blvih si ioned 5115755 t 'circulaia'pa age 7.8 suitablei'forreceivi' in Figure 2 of theQdra'wings, the low friction trumpet 65 is rotated to resultjin the strands and fitbein'glsub j'ected' to aininirhum of attrition and at the ame time resultin the strandsrbeing brought together at amateur;- sifable anglei Dnbeing b rou'ght together fat the apex of theballoom the individual strands"61"and $54 are-twisted together to formaplifeid'strand 67 which then passes into the "passageway 78 of the forming trunipet' 66; I Th'e'pre'ssure'of the blocks 74' and 75 jonthe twisted -straiicl further smooths 'out 'irre'gulari'ti'es andinakes the yarninore iiiiiform. Should "a knot appear in the twisted strand '67 below'the trumpet 66,'the resilient mounting of the block 74 allowsthe'knot'to pass without-breakage of the strand. 7 In'Figu're 3 of the drawings there is partially illustrated a modification ofthe invention substantially identical'to the embddi'rnentofFigmi'e" '1 except that the pig-tail guide 42 'ot Figure l'has been replacedby'a more complicated revolving flyer and trumpet. In this embodiment of the inventidn'there is illustrated al'shield 81 about which a ballo'onbf yarn is adapted to be rotated by a revolving spindle; not illustrated, A tubular trumpet 82 is mounted in axial alignment with the rotating spindle and'is carried by a suitable support 83. The trumpet 82 is adapted for rotation by virtue of bearings 84 and 85 and is retained in position by a nut indicated by the reference numeral 86 Mounted around the trumpet .82 below the support member 83 is a flange member 87 secured for instance by friction fit. The flange member 87 carries two diametrically opposed tubular pins 88 and 89 mounted at right angles to the longitudinal axis of the trumpet '82. Press fitted in the ends of each of the pins 88 and 89 is a wire loop fiyer'90 having three smaller loops 91, 92 and 93. The loops 91 and 92 are formed equi-distant 'on'either side of the longitudinal axis of the trumpet 83 while the loop 93 is substantially in line with the loops 91 and 92 but considerably further removed from the axis of rotation. p i

The operation of the modificationshown in Figure 3 is substantially identical to that of the embodiment shown in'FigureI. A first strand of yarn 94 is led from the peripheral edge of a disk flyer, not shown, through loop I 92?,"throi1gh Ioop92, through an axial passage 95 in the ereii'c' numeral 100 ke-1 mea n t l us r te ""96 is led iron; the. automatic tension cane-d n e s t t b f 'P e d he iiice 98, through the 160'991, '95 in truihpeffiziand' then to means along, withjthe firststiand 94'. When placed operation, the balldon', of the. strand 4 c es the five Wand trumpe 8, at y chroni sm with the spindle as aresultof the 'considerable moment of rotation exerted on thefl'yer 190 by the' strand 94 as it passes through the loop 932 The loops 9'1 and 92 being equidistant from of rotation of the trumpet 82 insure'that the two' strands 94 and 96 will oonver'ge'at e u al e es wi es ec to he p st an h b'y assi t n "1 1 2? t inment 9 unifd n p 'y' Fi u. *th 'il suaed g eii i vs lar to'that illustrated in Figured but employing-g novel tension e ualizin device generally indicated bythe ref- 7 figure; andi u tratedift'deen in Figure 5., AS'VVllltbSfiEQ fliromt ifi'd fe ings th "tenn qu i ing d u cem ri es b row ori nta e element' 9: Iiins each rowibeing; adapted to'r'e'oeive one strand of yariijimmediatelyl pri r the'strands being plied 7 together. The tension 'equalig ng device illustrated in the I berotrows.

drawings is gdes'i'g ned' to the tension in only two strands being *pli ecl together and therefore has only two ows: of pin'sff'with the meahplahe of eac hrowbeing at an anglebfi approximatelyd80i to the me'anlplanei of the other rowt As 'will be more apparent from the detailed description 'off the; equaliiing device to fcillow, liowev'er, the device can" be adap'ted 'to equalize tension in several strands by providing a row of pin sforeachof the several strands, the rows being Se positioned that the angle 'B- tween the. mean plane" of adjacent rows of pin s is approx1mately360fZ/rt wherein nir'ep'resents the total nurn- Witlt particular reference toFigures 4 and 5 of the drawings th'ereis illustrated a rotatable spiiidlelOl a yarn storagedevicelGZ carried by the spindle 101 and adapted to berotatedtherewith; and a disk fiyer 103'al'so carried by the spindle 101 and adapted to be rotatedtherewith. A stationary platiorm 104 is carried by'thespindl'e 101 whic hiis free: to revolve with respect thereto by vire f m st 9 ll e in .05- The p a f is r ilsdim mat ith the. pindle 10.1 y means o 811 e entr e ei ht 9.

h r t q mwlfl iqerri th cover .0 wh i seetioned and adapted to; be opened by virtue of hinge108. When closed the upper section of the cover is" retained in position by clip 1 991 An automatic tension control device of the gate type 'is mounted within the cover 107 in axial alignment with the rotatable spindle 101 and is supported .by the upper section of'tliecover 107- by n'iean's'oi.a'rrn 111 attached to'the c'oyer'by any. suitable means, such as by cementing. 7

Mounted in a 'suitableopening in the apex of the cover 107 is a tubulai me a er'11'2 andjournaled in the tubular member 112 by means 'of hearings. 1 13 and1 14 i s a shaft 115'rotat'able about the extended aids of spindle 101. The shaft 115 carries two diametrically opposed wire yarn guides 116 and 117 extending at right angles from the longitudinal axis of theshaft 115 and above each of the yarn guides 1-1'6 and117 are two rows of fixedv pins 118 and 119 mounted on theshaft 115.. t

Each of the rqwsotpins 1 1 an n e. Shaft 5 is pt ltg re ive st sl of mpa ed hr u h h wire guides ll'o and 117, the strands being subseguently plied together at a point substantially inaxial alignment with thespiniile 11 5, pins 118 and 119'are1i f6 ferably mountedat'a angle witnre pect to the shaft 11 ha h y kt lnd t app m i t an e to the strandot yarnwhichthey are adapted to receive.

As' best shown in Figure :5 alternate members of the pins H s and 119 are'clispbsed at aj'sliglitang'le for eka' mple less than 'zoean'a preferably about? with respect to each other thereby presenting a tortuous path for a strand of yarn threaded between alternate pins. The opposing faces of alternate pins in each row should be rounded to present a smooth surface to the strand of yarn passing thereover and can if desired be chrome plated or the like to increase their resistance to wear. The extremities of alternate pins are curved to form hooks which serve the purpose of retaining the strands in their proper courses at such times as might be necessary.

To prepare the device illustrated in Figure 4 for operation, a strand of yarn 120 is threaded through the passage 121 in spindle 101, through the orifice 122, around the yarn storage device 102 and over the peripheral edge of the flyer 103. The strand 120 is then threaded through the wire guide 116 and between alternate pins 118 and through the eye 123 of a pig-tail guide 124. The strand of yarn v124) is then led to a take-up device adapted to collect the strand at a constant linear velocity. A second strand of yarn 125 from a yarn supply package 126 on package support pin 127 carried by the stationary platform 164 is threaded through the automatic tension control means 110 and then into an axial passage 128 extending part Way through the rotatable shaft 115. The strand 125 is then lead through an orifice 129 in the wall of the shaft 115 immediately below the Wire guide 117. Strand 125 is then passed through the wire guide 117 and between alternate pins 119 through the eye 123 of the pig-tail guide 124 and then through the yarn take-up device alongside the strand 120.

When the device illustrated in Figure 4 is placed into operation, the strand of yarn 120 forms a balloon rotating about the cover 107 which in turns causes rotation of the shaft 115 which results in the strands 120 and 125 being twisted together below the eye 123 of the pig-tail guide 124 and immediately above the tension equalizing device generally indicated at 106. As previously explained, the tension in the strand of yarn 120 while in the balloon is retained substantially constant by the yarn storage device 102 so that it is supplied to the wire guide 116. at a constant tension. The automatic tension control device lltl should then be adjusted to supply the strand 125 to the wire guide 117 at substantially the same tension at which strand 129 is supplied to wire guide 116.

The operation of the automatic tension equalizing device illustrated in Figures 4 and 5 will now be explained. If the tension in strand 120 as it enters guide 116 is greater than the tension in strand 125 as it enters guide 117, the apex of the ballon, indicated at A where the two strands 'are being twisted together, will be pulled in the direction of the strand 120, as indicated bythe dotted line, and will thereby be positioned so that the apex may be represented at A. This results in the strand 125 being moved laterally toward the spindle 115 thereby increasing the contact of the strand 125 with the pins 119 and causing the strand 125 to follow a more tortuous path. At the same time the strand 120 is caused to move laterally away from the spindle 115 thereby decreasing the contact of the strand 125 with the pins 118 and causing the strand to follow a less tortuous path. As can be seen, results in the tension in the strand 125 as it meets strand 120 being increased to where it is substantially equal to the tension in strand 120 at the point of contact. It will also be seen that the tension equalizing device results in the two strands being brought together at approximately the same angle with respect to the plied strand thereby resulting in still greater uniformity in the plied strand. v

It should be emphasized that the tension equalizing device operates most eificiently for small differences in tension in the individual strands and that if the difference in tension becomes too great, tensions in the individual strands will not be equalized to a sufiicient extent'to result in a uniformly plied strand. If therefore whenthe device of Figure 4 is placed in operation it is noticed that the apex A of the balloon continues to describe a circle of appreciable diameter it is an indication that tension 10 in strand 125 at wire guide 117 is not substantially to that in strand 120 at wire guide 116. The device should therefore be stopped and the automatic tension control means adjusted to supply the strands to the tension equalizing device at a more nearly equal tension. When the device is operating properly, the apex of the balloon will remain in substantially axial alignment with the rotating shaft with only occasional small movements to one side or the other;

Having thus described my invention what I claim and desire to protect by Letters Patent is:

I claim:

1. A mechanism for plying together strands of yarn, saidmechanism comprising in combination means adapted to rotate, at a substantially constant velocity, a balloon of a strand of yarn from a first supply package about a second yarn supply package, tension control means adapted to retain the tension in said strand of yarn in said balloon substantially constant, adjustable tension control means adapted to supply a strand of yarn from said second yarn supply package at a uniform tension substantially equal to the tension in said strand of yarn in said balloon, guide means adapted to bring together, at substantially the apex of said balloon, said strand of yarn from said second yarn supply package and said strand of yarn in said balloon, whereby the strands' are plied together, and means adapted to with.- draw the plied strand of yarn at a substantially constant linear rate, said guide means comprising a forming trumpet adapted to smooth out irregularities in the plied strand.

2. The apparatus of claim 1 wherein there is employed, in combination'with said forming trumpet, a

rotatable low-friction trumpet adapted to bring the strands together with a minimum of attrition and at a more nearly equal angle with respect to the plied strand to thereby improve the uniformity of the plied strand and the lay of the individual strands in the plied strand.

3. A mechanism for plying together strands of yarn, said mechanism comprising in combination means adapted to rotate, at a substantially constant velocity, a balloon of a strand of yarn from a first supply'package about a second yarn supply package, tension control means adapted to retain the tension in said strand of yarn in said balloon substantially constant, adjustable tension control means adapted to supply a strand of yarn from said second yarn supply package at a uniform'tension substantially equal to the tension in said strand of yarn in said balloon, guide means adapted to bring together, at substantially the apex of said balloon, said strand of yarn from said second yarn supply package and said strand of yarn in said balloon, whereby the strands are plied together, and means adapted to Withdraw the plied strand of yarn at a substantially constant linear rate, said guide means comprising a rotatable trumpet carrying a flyer adapted to bring the individual strands together at approximately an equal angle with respect to the plied strand. 7

4. A mechanism for plying together strands of yarn, said mechanism comprising in combination a stationary shaft having an axial passage adapted to receive a first strand of yarn, adjustable automatic tension control means adaptedto feed said first strand of yarn into said axial passage at a substantitally constant tension, a rotatable spindle adapted to rotate about said shaft, said spindle having an orifice in the wall thereof adapted for passage of said first strand of yarn, a support platform carried by said spindle and rotatably mounted thereon, means for preventing rotation of said platform with said spindle, a yarn supply package support pin mounted on said platform, adjustable automatic tension-responsive feed-back yarn tension control means carried by said spindle and adapted to control and. maintainsubstantially constant the tension in a second strand of yarn emanating from a supply of yarn onsaid support pin,

sses .a disk flyer mountedon said spindle and adapted to assist in the control of a balloon of said first strand of yarn rotated about said support platform and the structures supported thereby, automatic tension control means adapted to be responsive to slight variations of tension in said first strand of yarn issuing from said orifice and also to variations in the size of said balloon to thereby control and maintain substantially constant the tension in the yarn in said balloon, guide means adapted to guide together said first strand and said second strand of yarn at substantially the apex of said balloon thereby resulting in said first strand and said second strand of yarn being twisted together to form a singlep ied strand, means adapted to withdraw said plied strand under tension at a V substantially constant linear rate, and an adjust ble te 7 :sion control device adapted to supply a strand of yarn to. said axial passage in said shaft at a substantially constant tension, said guide means comprises -a rotatable tension equalizing deviceadapted to substantially elimi- Znate small differences in the tensions in the strands immediately prior to their being plied together. I

5; .A mechanism for plying together strands of yarn said mechanism comprising in combination meals adapt- Fed to rotate, at a substantially constant velocity, at balloon ofa strand of yarn from afirst supply package about .a second yarn supply package, tension control means adapted to retain the tension in said strand of yarn in said balloon substantiallyconstant, adjustable tension control means adapted to supply a strand of yarn from said second yarn supply package at a uniform tensionsubstantially equal to the tension in said strandof yarn in said "balloon, tension equalizing guide "means adapted to bring together, at substantially the apex; of said balloon, said strand of yarn fromsaid secondyarn supply: package and said strand of yarnin said balloon,

Iwhereby the strands I are plied together, and means adapted to withdraw the plied strand of yarn at a substantially constant linear rate, said tension equal izing .guide means comprising an elongated support member and a plurality of rows of fixed pins, the pins in each 'of said rows being so disposed that the axes of alternating pins "extend in planes diverging through a small .angleless than about 20, the mean plane ,of each row of pins being substantially radial to the longitudinal axis of said support member and the angle between the-mean planes of adjacent rows of pins being approximately 360/n wherein n represents the total number of rows.

6. Flying apparatus comprising a rotatably driven member adapted to drive a firststrand in a'balloon about 'a second strand and a source of supply for said second strand, a second member freely rotatably mounted in spaced apart substantiallyaxial alignment with said driven member and adapted to be rotatably driven about the axis of said balloonvsolely through the rotating engagement of said strand balloon therewith precedingthe xplying of said first strand with said second strand, anda 9. Apparatus according to claim 8 wherein saidsecond and third strand tensioning means are interacting and self-balancing in their tensioning action upon said first and second strand, the tensioning action of said second strand tensioning means being responsive to the differential tension in-said first and second strands as it proceeds from said second and third tension device, the tensioning action of said third strand tensioning means being responsive to the differential tension in said first and second strands as it proceeds from said second and third tension devices.

10. Apparatus according to claim 9 wherein said second and third strand tension devices each function on the principle of variable sliding surface contact bysaid yarn,

said sliding surface contact varying in response to the difierential tension in said first and second strand as they proceed from said second and third tensioning means.

. 11; Apparatus according to claim 10 wherein the output tensions of eaeh of said first and second strands as -theyproceed from said second and third tensioning means are opposed to one another, the extent of surface A contact of each of said first and second strands with said third and second tensioning means respectively being a member adapted to drive a first strand in a balloon about a second strand and a source of supply for said second strand, a second member freely rotatably mounted in spaced apart substantially axial alignment with said driven member and adapted to be rotatably driven about the axis of said balloon solely-through the rotating en- :g'agement of saidstr'and balloon therewith preceding the fplying of said first strandwith said second strand, and a strand tensioning means disposed on said second freely rotatable solely-strand-driven member and adapted to tension said second strand.

13. Plying apparatus comprising a rotatably driven member adapted to drive a first strand in a balloon about a second strand and a source of supply for said second strand, a second member freely rotatably mounted in spaced apart substantially axial alignment with said driven member and adapted to be rotatably driven about the 'axis of said balloon solely through the rotating engagement of said strand balloon therewith preceding; the plying of said. first strand with said second strand, and tension balancing means on said freely rotatable solely- 'strand-driven member and adapted to contact and tension each of said first and second strands.

14. Plying apparatus comprising a rotatably driven member adapted to drive a first strand in a balloon about a second strand and a source'of supply for said second strand, a second member freely rotatably mounted in spaced apart substantially axial alignment with said driven first strand tensioning device disposed on rotatable with said first rotatably driven member, said first strand .tensio'ning device comprising a yarn storage variable 'wrap'angle tension device inc ludingrintereonnnected axial .-and transverse bores in said rotatably 1driven member and a peripheral strand engagingsurface on 'saidrotatably driven member adjacent, said transverse bore.

7. Apparatus accordingto claim 6 whereinsaid second freely rotatable member has a guide member'thereon thi'r'd strand tensioning means disposed on said .freely rotatable solely-'strand-driven member and adapted to :contact and tension-saidifirst steand.

member and adapted to be rotatably driven about the axis of said balloon solely through the rotating engage ment of said strand balloon therewith preceding the plying of said first strand with said second strand, and

tension balancing means on said freely rotatable solelystrand-driven member and adapted to contact and tension .-each of said first and second strand, said tension balancing means including a surface for variable sliding surface contact by each of said first and second strands, the degree of said sliding surface contact by each of said strands being proportional to the differential tension in said first and second strands as they proceed from said tension balancing means.

15. Plying apparatus comprising first and second strands and individual supply packages therefor, a first rotatably driven member adapted to drive said first strand in a balloon about the supplypackage for said second strand, means for rotating said rotatably driven member, a-second freely rotatable member disposed at one end of said balicon and in spaced apart separate relation from said rotatpably driven member,,-.gui de mea s n said freelygotatable assess? 13 member and adapted to engage said first strand balloon for rotation of said freely rotatable member solely by the energy of rotation of said balloon about the axis of said balloon, and a strand tensioning device disposed on said strand-driven freely rotatable member and adapted to contact and tension at least one of said strands.

16. Plying apparatus comprising first and second strands and individual supply packages therefor, a first rotatably driven member adapted to drive said first strand in a balloon about the supply package for said second strand, means for rotating said rotatably driven member, a second freely rotatable member disposed at one end of said balloon and in spaced apart separate relation from said rotatably driven member, guide means on said freely rotatable member and adapted to engage said first strand balloon for rotation of said freely rotatable member solely by the energy of rotation of said balloon about the axis of said balloon, and a variable wrap angle strand tension device disposed on said rotatably driven member and adapted to contact and tension one of said strands.

17. Apparatus according to claim 16, further comprising a strand tension device on strand-driven freely rotatable member and adapted to contact and tension said second strand.

18. Plying apparatus comprising a rotatably driven member adapted to drive a first strand in a balloon about a second strand and a source of supply for said second strand, a second member freely rotatably mounted in spaced apart substantially axial alignment with said driven member and adapted to be rotatably driven about the axis of said balloon solely through the rotating engagement of said strand balloon therewith preceding the plying of said first strand with said second strand, and a first strand tensioning device disposed on and rotatable with said first rotatably driven member, said first strand tensioning device comprising a yarn storage variable wrap angle tension device including a strand guiding bore in said rotatably driven member and a peripheral strand engaging surface on said driven member adjacent one end of said bore.

References Cited in the file of this patent UNITED STATES PATENTS 843,448 Fahr Feb. 5, 1907 1,233,593 Macfarlane July 17, 1917 1,356,834 Smith Oct. 26, 1920 1,984,538 Mougey Dec. 18, 1934 2,179,247 Arnold Nov. 7, 1939 2,343,535 Clarkson Mar. 7, 1944 2,442,775 Nelson June 8, 1948 2,732,680 Vibber Jan. 31, 1956 2,752,749 De Halleux July 3, 1956 FOREIGN PATENTS 523,245 Belgium Oct. 31, 1953 

